I guess it's because comic books are a visual medium that the art makes all the difference.

Anyway, the introduction of Rob Liefeld as regular artist heralded the beginning of the end.  Yet he was actually on the New Mutants for about a year before it ended.  That's thirteen whole issues (and one annual) of a drastically different title.  Instantly it became a much more violent title.  Freedom Force became a group of real villains.  The MLF, Stryfe & Cable were thrown into the mix straight away.  All the fantasy elements of Limbo, Inferno & Asgard ditched in favour of muscles, guns, terrorism and more guns... Where's the Love?  Where's the fun??

It makes it so hard to appreciate those later issues, but I've got a job to do... I'd better get reading :p

(It also makes it all the more easier to love Zeb Wells & Diogenes Neves' work, and there's only been two issue so far!!)